Unfortunately, if you use the Kotex RR to pay for more Kotex, it will NOT print again. You would have to buy the Kotex, use the RR to put towards the Finish, and then use the Finish RR towards the Kotex, so on and so forth. It's called rolling the rewards! I know using a filler can be a pain sometimes, but if your Wags still has any Easter candy on clearance, you can probably find fillers for ~10 cents. Otherwise, there's always caramels for 35 cents. Probably some other cheapo stuff too!
Martin's potato bread/rolls
Deer Park 3L jugs
Deer Park/Dasani/Aquafina 24-packs