A ftriend is currnently on his way from Maryland to Montreal in a, new
to him, boat, equiped with a relatively new vacuflush head. Problem
is that the head is clogged and he's trying to avoid taking the system
apart while underway to clear the clog.

Given that some pump out systems use a vacum tank and develop a fair
bit of suction power is it worth it to try and clear the blockage that
way? I.e. block the tank vent and go get a pump out and hope that
this dislodges the clog. This would of course depend on being able to
equalize the relative pressure in the holding tank through the
Vacuflush head during the pump out. Is this possible?

Many tanks in advance.

Matt