Please explain walgreens deals to me??? RR? How does it all work?

ThAnKs!!!!
Maybe this will help, I wrote it out for my mom:
Get 9 Crest Pro-Health or Night Pro-Health 4.2 oz. toothpastes.
Use coupon from page 22 of the May Easy Saver catalog available in the store.
Total comes to $22.50 on sale. Coupon takes off $13.50. You receive two $10 Register Rewards ($20) that can be used to buy most anything else in the store (can’t be used on the same deal again though).
This is a profit of $11 in Register Rewards. If you have manufacturer coupons, it gets even better.
___________________
There are many items this week that give $20 in Register Rewards if you buy 9. If you look at the ad items and can get the item for less than $2.22 after mfg. coupon, it’s free after Register Reward (excluding tax).
CoverGirl items are included and you only need to buy 6 to get the $20 in Register Rewards because the buy one get one 50% off makes the register think you purchased 9 (but must not get more than 2 items with the same UPC). Combine this with the coupons from Sunday’s Proctor and Gamble coupon insert. The lowest priced items are eye pencils with sharpener, big sharpener, foundation sponges, etc. at $2.99 (and 50% is taken off the 2nd item). Be sure to use the free blush when you buy 3 CG items coupon if you have it.
Buy 9 Charmin flushable wipes and use coupon from the weekly ad plus any 25 cent Charmin coupons and they’re a little more than free after the $20 Register Rewards.
Cascade and Mr. Clean products end up being free if you have enough mfg. coupons, or can combine them with other items above to total 9 items.
Register Rewards are coupons that print from a machine called a catalina. This machine also prints other mfg. coupons that are triggered from transactions, for example, buying Charmin wipes triggers a $2/2 coupon this week for Cottonelle wipes.
Also, register rewards expire 2 weeks after they print. Some stores will only accept one per transactions, but the policy is supposed to be one per item because it's a mfg. coupon. For example, if you bought 3 boxes of cereal and you had 3 mfg. coupons for them, the register reward wouldn't be accepted UNLESS it was used first, but no store has ever scanned it first for me, they always do it last, even if I ask them not to. If you bought 3 boxes of cereal and used 2 mfg. coupons and one RR, it would work. Hope that makes sense, I don't know if you shop at CVS too, but Walgreens can get really confusing and their receipts are weird too because they charge full tax on every item before coupon (in MN, don't know about other places).