Firstly apologies for a total lack of information but

I was watching a programme the other day and they looked at a man who
had given up his job and invested his savings to market a moveable
bath sealer, it was a white moving plastic fitting that moves up and
down.

I think that it was on the money programme but I am not sure - I will
search but hopefully someone else will have seen it. It certainly
seemed to offer an alternative to silicon sealant.