Well remember the bags of OM15 full of what looked like glitter (pump remnants) when doing an hydraulic flush. Never managed to be so affected down route though. Most of the stoppers I got were related to propellers.
Aha, had them as well - Gitz Seals being favourite. Last one was in Mombasa with Robbie Kendra (RIP) . . . (and a certain Mr Moffatt of the Fred variety).