For what it's worth, You can shop at COSTCO without a membership. Go to the service desk and purchase a giftcard, then enter through the entrance with said gift card, shop, checkout and use gift card to pay, and if you like purchase another gift card and repeat, I have purchased gift cards for friends to try it. As far as Kirkland Scotch, I plan to give it a try.
The craziest place I have ever purchased alcohol is in Utah, that be some crazy rules place, only 2.0 alcohol sold other than State run Liquor stores. I thought I was going to be run out on a rail, at 9:00 am waiting for them to open, I commented, "I am glad to see that I am not the only alcoholic in Utah" Didn't sit well with the others inline! Then I drew a crowd as I loaded al of the stuff on my motorcycle to leave, I think I overheard bets being made as to if I would make it to my destination!