Grunge Off Cleaner Residue - Safe?

Hello all. I've recently used a product that was recommended to me through a friend called Grunge Off Super Soaker. I filled this (pics) entire 2 perc dome bong bong with Grunge Off (it was pretty dirty) and let it sit overnight. Rinsed it and was left with a crystal clear bong as well as this salt deposit looking residue. I've shaken, stirred and mixed but can't get it out of the bottom of the dome compartment short of thinking of slipping a pipe cleaner in to see if I can scrape it off.

The product claims to contain no harmful abrasives with the added benefit of being biodegradable so I've continued to use this bong.



Advice appreciated ty.

Heat it. Put it over a burner to get it hot. Don't know that I would let it make direct contact but low temp and let it warm the solution. Maybe add a touch of baking soda when warmed and see if it reacts. If it doesn't add a little more. If it still doesn't dump some vinegar in. One of the two, acid or base, will react with the precipitate. Or should. Last resort contact the customer service number on the can and tell them what you did, what happened and ask how to resolve it. Tell them it's your tobacco pipe.

I've been using grunge off regularly for a couple of years and usually only need a few minutes of soaking before rinsing it out. I have never seen any kind of residue from its use. I have to wonder - was that there before and you just couldn't see it because the bong was dirty? Anyway, to get rid of it now...heat, baking soda, vinegar are all fair ideas since you aren't sure what the substance is. If that doesn't work you could try isopropyl alcohol and coarse salt as well which is another typical kind of bong cleaner...but don't heat the IPA with a flame.
BTW, it is reusable. I just pour the cleaning solution back in the bottle until the next time so I only lose a little with each evolution. After a while, it can get a little dirt collecting in the bottom so you can filter it or just pour off the last bit of the bottle which contains most of the grunge.