2nd attempt to get a digitiser stuck down

Followed the guide to do a digitiser replacement and all went really well.

Next day however, as soon as I used the ipad for 10 mins, the bottom edge and left hand edge of the screen have started to lift from the back / bezel. I tried heating the edges and leaving the thing for 24 hours with heavy books pressing down on the back.

It stayed stuck for 20 mins that way.

SO...

I've ordered another set of adhesive strips to have a second go but reading a few other sites as well there seems to be a suggestion that I could get away with slapping on the new strips., heating and pressing as before and somehow the combined adhesives will work together to give a reliable bond.

Must say, that seems like bollo... rubbish to me. If one adhesive layer was weak, surely sticking a better one on top of it still just leaves the weaker layer to peel away again next time?

What would the wisdom of iFixit be? remove LCD and digitiser again? Clean down one or both mating surfaces with isopropyl to give clean bonding surfaces and the best chance of a good strong bond? Anything else I should be looking at to see if something isn't sitting quite as flat within the back housing as it should be?

All advice gratefully received as you'll understand that I really, really want to get the %#*@ thing to stick properly this time!

Thanks