My preferred mounting method is clean(ed) bar and clean(ed) grips. Then I slide the grips on using compressed air.
That has "never" failed me.
If I don't have compressed air, I prefer to use rubbing alcohol or methylated spirits.
Seems to work too.
Water has been kinda-sorta for me. Sometimes it dries out and leave a "solid" bond. Sometimes, there's still a lasting creep or squirm.
The generally recommended first fix is to use hair spray to settle the grips. It dries up into something shellack/veneer-looking and locks the grips in place.
IME, It'll take some days to get full lock, even at room temperature.
You could probably use a wide range of liquids, as long as they have some drying characteristics and don't attack the rubber. I think I've read of one guy who used spray paint. The advantage being, hair spray CAN become unsettled by water. Paint won't.
I've tried using double-sided sticky tape on open-ended grips. Apply to bar, put a strip of tough plastic over tape. Leave a long loose end that doubles back over the tape. Slide grip on, pull to remove plastic strip and expose the grippy side. Rub/squeeze grip to make good contact with tape, done.
Probably the most fiddly process, but then and there, that was what I had to work with.

The MTB crowd sometimes use pinching collars to lock the grips in place.
You could simply try some zip ties pulled tight at the inner end. Easy, reversible, low-cost.