i've watched them replace 3 of mine and they always cleaned the area before they put the glue/urethane stuff on and also cleaned up their mess when they were done
and why arent these people calling safelite to get the rework done when they have a lifetime warranty?..... which i've also used, they fixed a chip and didnt get all the air out so there was a bad glare, like sliver/crack so they came out and replaced the windshield.... it probably wasnt that bad to the normal person but my eyes are fucked up and it was messing with my vision.