S.L.
We had the same thing happen at Bear Lake last summer. I actually posted the same question on here. I really did find anything that worked. The swimming suit still has sand in it. I think it has started to get better over time. She just wears it how it is for when we are just swimming in the backyard or beach (don't want to ruin another!) Good Luck!!! I will be curious to see if you get any good ideas on your post.