I thought of another couple things you can try.
Find an auto store or something like that which has the anti-slip pads... If they get dirty just wash em with some mild soap.... nothing sticky to clean up, and they are resistant to mold.
If you want something bigger... bath tub mats may get you there too.
I was looking at your first post on this, again...
I am just wondering if the spikes were not out does the pedal rest on just the velcro or is there rubber stoppers on the bottom? You didn't mention testing it out with the spikes retracted so I have to ask
