Vacuum seal your bags, that shouldn’t alert a dog (as long as you are careful not to get any residue on the outside).
Maybe use that highlighter or PEPSI can hidden stash.
But probably the best advice I can give you for the school zone; roll joints and sell them, so you can easily eat the whole stash without too much of a big deal.
I had a friend get out of a charge because he rolled up all his herb. We were in gym, and he was in health when they surprised us with a random search. I was in the same hall and aware of the 6 joints in my friend’s hoodie. He was sweating bullets, but was way down at the end of the hall, fortunately towards the end of the search line. He opened the bag of joints inside his hood, and discretely ate 2 joints at a time. The dogs didn’t alert on his bag though, maybe because the weed wasn’t in direct contact with the bag? If he had 4 eights rolled up individually in his pencil pouch… he would have been fucked, without a doubt.
If you are selling in school, you had better be charging extra for the crazy risk that comes along with something like that. It’s not worth it any way you look at it…