one use of word Mollag is 'buoy' or something that floats - see http://www.ee.surrey.ac.uk/Contrib/manx/fulltext/mr1911/ch07.htm

however a Mollag band is described in
http://www.ee.surrey.ac.uk/Contrib/manx/towns/castltwn/qual.htm
and also Hunt the Wren which may be your 1st query

snotty bridge presumeably means one that drips water