You are correct that BS is alkaline and LJ is acid. They do tend to neutralize each other's PH. That happens in a redox (reduction /oxidation) reaction. The advantage is, it helps to remove the crud on your bud. It might not matter to your crop but it can make a big difference in taste if you had to use any insecticides, are in a dusty environment, or use foliar feeding, among other things.Thanks Urbanmonk for the info. This is my first grow and do much info is out there. Much of it accurate and helpful but some is not so accurate. I watched a video this morning where this guy washes his buds after harvest and before drying. He mixed it in a solution of lemon juice and baking soda. Acid and an alkaline which I would think cancells eachother out. He never states the advantage of it.
I've done both for years. How much it helps depends on the crop. It never hurts anything when done correctly. I grow indoors and out. Outdoor crops are covered in dust, bug and bird shit, and I usually have to resort to some kind of spray for pests. The amount of crud that comes off is significant. Washed buds still test as well for THC content. Doc recently had some tested at more than 32%.There is a whole topic on the bud washing thing here too, many folks swear by it as you will tell if you read thru the topic. I'm just too "old school" I guess as it just seems "so wrong"......to each their own, and whatever works for you more power to you. On my 2nd grow so I'm seriously still learning the "how to grow right" part, almost past the "flying by the seat of my pants" stage at least LOL.
Wash on left / rinse on right. The top photo is from plants w/o foliar feeding. The bottom photo is from plants with lots of foliars. It got a third dunk/rinse in a bucket not shown. I'm happy not to ingest all the crap the wash left behind (including a few bugs).
YMMV. I'm not trying to convince or convert anyone - just giving you my experiences.