Very small numbers (only half a dozen) but with working full time sponging is essential for me and it works really well. Plan which week to lamb in and work back from there. Last year used a ram lamb (end of August) and pulled sponges over three consecutive days and all ok first time. Only negative for me is putting the sponges in - not my favourite sheepy task!
With only half a dozen I don't see any point in pulling them out on different days. May as well do them all on the same day. One ram can manage 6 in a day.
I sponged for the first time last year - it worked very well. Ram went in after 48 hours, and I mated each ewe individually - ie in a pen with the ram, let him do her twice, then let the girl out. Give him 5 mins rest - he can sniff the pen of girls who are waiting patiently .... then bung in another ewe, and repeat until they are all done. Then put him out with the ewes in the field for 35 days, to make sure he covers any repeats (raddle after 2 or 3 days). This way it just guarantees that he covers all of them equally and doesn't focus on the first one he gets to.
All of mine lambed over a long weekend, bar one, who lambed 17 days later.
I'm doing the same this year, but putting the ram in after 36 hours instead. And to minimise the time I need to take off work I'm timing it so that they lamb at Easter.
I sponged my ewe lambs too ... which was fine apart from I couldn't get the sponge in a couple of them.