Ocean - I currently have +-40 hermits in my main display (and 2 in my sump) - they do indeed work quite hard. BUT, I have found that NOTHING seems to beat my sea cucumber...... It REALLY sucks like an electrolux! It cleans the top 1cm of my DSB (in-tank) like NOTHING else I have seen before!
No - unfortunately don't have any pics (I will find some pics and post them of the TYPE of sea-cucumber)..... BUT, it has been in my tank now for about 2 months - and it has only been growing (doubled in size already!) since I got it..... I am very happy so far that I got it!