I don't. At least the ones I got gifted[1] fight you every step of the way. The silicone is very thick and stiff. It's hard to remove air by submerging them, d

I don't. At least the ones I got gifted[1] fight you every step of the way. The silicone is very thick and stiff. It's hard to remove air by submerging them, depending on what you put in there, there are always some pockets of air remaining. And the way they seal is very fiddly. One of the sealing clips broke after a few uses. Maybe it gets easier with experience, but some things just shouldn't be that aggravating. On the other hand, a cursory search shows that there are many other products available that may be more sensibly designed. [1] PureSiliconeWare is the brand name