i don’t have answer to your specific question, but i try not to use any chemicals to clean the tray inner surface. I use a household silicon spatula to wipe the silicon layer in the tray, the one you’d use in your kitchen to scrape out the pots of mayo & the lot.
It’s cheap and made out of soft silicon, so it won’t damage the silicon layer in the tray. Another plus: on it’s backside, it has exactly the roundness your resin tray has in its corners, so the spatula fits in perfectly. For better handling, i just cut/saw off the handle so i’m left with only the silicon part to work with afterwards.
You can push the spatula fairly hard onto the silicon tray surface to remove any debris, and scrape sidewalls for same reason.
When 99% of the old resin is removed (and filtered for re-use), i pour in very little clean resin again, and repeat the procedure once more. All dirt is gone now, silicon layer in tray is not damaged it is and cleaned with product it is supposed to hold. Works like a charm, costs next to nothing and spatula is available in any grocery around your corner. Give it a try.