I've never had a draw set up i always used shallow containers. and to get the skins out just blow on them and they go flying everywhere. dead ones pretty much got to pick them out. or could try not sure if it would work but some kind of strainer pick a bunch up at a time and let it set above the substrate you use so the live ones crawl threw after a few minutes or hours. depending how active they are then you might have to pick a few remaining live not as active ones out.