Never seen a guaze in ours (late DG/DJ)

What I'd do is to remove the tower (carefully making sure the 4 m6 nuts/washers
don't drop into the crankcase

) and having stuffed the hole with a rag to prevent losing something else down the hole, give it a good old blow out with WD40 or similar. Dry it well and replace it ... checking the base O-ring and again be carefull with the nuts etc.
Ian.