In order of priority until bead seated: air canister type bead-seater, tire goop, then donut thingy. If you have tire goop then donut is not needed? Too finicky to use in the field. May work when tire goop melted too much from heat (110 degree F, desert climate) to be effective as space barrier, so combination of liquid form tire goop and rubber donut may prove effective.
Let me say having the semi-circle multi port attachment was essential. This worked great! There were two issues: first; the locking ring didn’t fit on both attachments so I couldn’t tighten the nozzle in the right position. It didn’t seem to matter though; even loose the attachment worked. Second; the fill valve is very close the air attachment point. A larger handle with more offset would make it much easier to use. I would buy it again regardless of these two issues!