I have watched a dvd by Paul Metcalf and when he catches a swarm in a skep he ties a bed sheet around it till he gets it to the hive he wants to put it into. He then unties it and shakes it either into the hive , or a board at the entrance and lets them walk in.
I have had three calls for swarms last week and passed them onto others as I am up to my limit at the moment. The others were very happy to pick them up.
PH I agree you just got to realise when its a no go.