Do you not like any of the silicone tips? Those can be cleaned. I do not use foams at all on any of my iems. I personally hate the feeling of them and it is gross to me that they can harbor germs. If I did use foams I would probably change them every week or two. I have so many just sitting in bags unused... ones that were included with various iems. I use various silicone tips depending on the fit of the iem. At the moment I have Spin-fits on my iBasso.