I too have experimented with waterproofing by painting cosmesis cover with latex. I use a compression sock to cover the foam cosmesis and painted over that. I bought an open-toe compression sock and further cut it at ankle below the place where foam cosmesis and the foot shell meet. However I have problem with foot shell - cosmesis meeting point as the foam cosmesis tends to compress, creating a gap. That is because of ankle movement that causes the foot shell to push foam cosmesis upward.
I think Frederick has done a lot of research and testing to get a leg that gives its user more freedom and outdoor life, and he likes to share his effort with other amps by trying to sell his idea to prosthetists. Hats off to him for that.
Yes indeed, Jukka, it would be a grand thing to be able to get into a shower without all the usual procedure - in fact if I was in a strange place, I probably couldn't use a shower, as for me it involves delegging and using plastic stools to manoeuvre myself in and out of the shower.