as long as it dissolves complelty it will be fine, have you looked into the mirena IUD though? i have one, not for protection, DH is fixed, but to control crazy periods, and its safer and you wouldn't have to worry about it absorbing.
UC for 8 years, before finally kicking its butt and having a permanent ileostomy April 17 2007!
-I have gone to find myself, if i get back before i return, keep me here-
No matter what kind of day you are having, take five minutes to sing loudly and dance like a fool!