We always use water based lube. I just had an 11 hour continual anal sex-athon with hubby, but we went through a tube and a half of lube. I was thinking that, since no toys were involved, silicone might have "lasted longer". However, I always worry that silicone is not a natural body substance and could screw up my gut. Anyone care to share input on this. I would love to hear from folks who do use silicone lube. Is it really better for long anal play?