I got a power strip (this one) that doesn't have holes on the back for mounting to the wall. I had figured I'd use Command Strip adhesive and be done with it, but it has little grippy feet on the bottom that raise it up off of the surface just enough that a command strip wouldn't grip securely. What else might work? Since it will have power cords (and USB cables) plugged and unplugged every now and then, it needs to be able to stand up to forces perpendicular to the plane of the wall.
To avoid damaging the unit and loosing the warranty, do not remove the feet or permanently fix the unit directly to a mount or wall.
Instead I would suggest making a bracket that would clip over the unit and then mount the bracket to where you want to place the unit.
Cable Tie: With a block of wood the size of the unit, drill two holes through the width of the block, making sure the holes are in a place that when cable ties are thread through, they will not interfere with any of the sockets. mount the block in position on the wall, feed the cable tie through the holes and tighten around the unit.
Metal Strips: 2 x Perforated metal strips mount directly to the wall or mount to a block as above.
Molded or Routed bracket: create two brackets that will sit over and support either end of the unit. Wood blocks routed so they fit over each end of the unit leaving the sockets free these routed brackets can be mounted to the wall with the unit sitting inside. If you are able to find plastic that can be molded or routed then do you could use this method and this would be the smartest looking option.
Is it not possible to use a knife or other sharp edge to remove the feet? Most of the rubber feet I've seen are either attached via grommets--essentially thin pieces of the rubber which extend through a small holes with a slightly larger part at the end to hold it in place. Cheaper companies attach flat ones with adhesive.
If removal is not an option, your best bet is still with Command adhesive for the wall adhesion. However, what you will want to do is attach something to the underside of the strip (using a thin adhesive strip or, ideally, glue+clamping) that will increase the thickness to the same level as the feet.
I'd probably use a light wood like balsa or bass from a hobby store, as they are available in various small sizes and a large range of thicknesses. You may even be able to find a piece that is already the right length and width in their selection! (Be sure to take the power strip in with you to test for thickness length x width.) If none with the proper thickness will adequately fit, just get a slightly larger one, cut it small enough to fill most of the area, paint it to match the wall or strip (if desired), and attach it with your desired adhesive to the strip. Apply the command strips to the other side, following the supplied instructions, then attach it to the wall.
This will work perfectly, and you likely have something around your house already that you can modify to work (honestly, even a couple layers of carefully glued, trimmed, and painted corrugated cardboard could look professional! You would be surprised!) Honestly though, if it were me, I would probably find a way to remove the feet. ;)
I glue them to an oversize piece of wood then attach the wood in the normal way.
I roughen the plastic surface with sandpaper to give the surface microscopic jaggedness (called "tooth"), then glue them to the wood with a good 2-part epoxy and correct adhesive filler. The epoxy will engage into the jagged surface and won't just pop off, as it would with unaltered plastic.
For the feet, use a pen or pencil to transfer the marks onto the wood, then use a drill to relief the wood where the feet go. (before you glue, obviously). If you drill it just slightly deeper than the feet, you can also fill that space with epoxy, and it will help grab.
Of course you know, the electrical code only allows power strips with flexible cords for temporary use - not to be used as a substitute for the permanent wiring in a building. The code-legal way to do this same thing is surface conduit coming out to receptacle boxes, then use smart receptacles to switch the loads.
Look at a multioutlet assembly instead
Since this is meant to be a permanent/indefinite installation, I would look into using a surface raceway starter box and a length of surface raceway to connect the power source to a multioutlet assembly (often known by the trade name Plugmold™, image for exposition only):
These are like power strips, but designed and UL-listed for permanent wiring, mounting, and usage. One can fit a wall switch and surface box into the surface raceway feeding it if one wishes to be able to turn it on and off, for that matter.
- With the power strip unplugged, unscrew the screws that hold the plastic casing together.
- Drill holes in the bottom piece of the plastic casing (the piece that will be against the wall).
- Hold the bottom casing against the wall where you want it installed, and mark the wall where the holes are.
- Screw screws through the holes (from the inside of the power strip) and twist plastic wall anchors onto the screws (use strong, medium-large ones). Make sure the screws draw the anchors firmly against the bottom of the power strip.
- Re-assemble the power strip.
- Drill holes (smaller than the anchors) where you marked the wall, and push the power strip against the wall, inserting the wall anchors firmly into the holes.