I know it depends how much you use it, but approximately how often do you have to change flowable silicone response?
It mainly depends on the recess and how well it is applied. A bad job might last a couple hours to a week. A good job could last between a couple months to a year or more.
What if I just wanted to use a rubber o-ring gap?
Those will hold silicone very well, but it still requires smooth application.
yeah the o-ring recess holds sealant really well. I put white rtv into my DM and its been in there now for 6 months with out fail.