First off, two feeding attempts already and you got him 6 days ago? You should have left him alone for a week to adjust and wait a week after he refused the first one. Secondly, have you figured out how he escaped? If you don't find it and fix it then there's no point in putting him back in as he will just escape again.
As for finding him, if you have cats or dogs watch them carefully. It's in their instincts to hunt small animals and they can be a huge help in finding an escaped snake as long as you're very careful. Check things such as couches and recliners and bed frames that he could have crawled up in to. Check all along your walls for any gaps or holes he could have fit through. Once you find where he is if you can't reach him put his hide and a f/t rat/mouse on a heat mat and water nearby and he should hopefully go in there. If he doesn't come out on his own then you may need to carefully do some "remodeling"