I've used predominantly RMC and Odies for interior finishes, flooring, cabinets, tops. Buy a replacement pad of your choice and dedicate the old one for use with finishes. Keep sanding separate and visa versa. Abrasives will stick better without a bunch of Odies gunked up in the fast-fix.
You can order a 5 pack box of 16" 3M floor buffing disk for +/- $30 (Amazon). I cut several 150mm from these.. The disk are maybe 3/4" thick. If it feels a bit wobbly at 90mm diameter, the white pads from Odies Oil are thinner (but also seem very expensive). I think I've picked up individual 16" buffing disk from Home Depot also. Check the rental store if you're short on time.