I guess I'm just getting old and ornery. NOBODY in a store intimidates like that.

Just remember: YOU are the customer. THEY want your money. You DON'T have to give it to them.

Rule 1: The Customer is ALWAYS right.
Rule 2: When the Customer is wrong, Rule 1 applies.
Rule 3: If the Customer is wrong, and Rule 1 does not apply, then the Customer will become an EX-Customer.
Rule 4: An EX-Customer is worth 10 current Customers, as in: One "Aw, nuts, these guys are terrible" undoes 10 "Yeah, these guys are great!". (check out eBay--1 neg is actually the equivalent of 100 positives!)

If the clerk doesn't know what Liquid Chlorine is, YOU can say "You mean YOU don't know what liquid chlorine is? I thought ALL better pool stores carried it!"