Perdo Vim.
Unraveling the Fabric of Vim, at touch range, I dissipate the invisibility spell. Quite easy to do, btw (at touch range, this cancels base + 3 magnitudes of spell lvl IIRC)
Unravelling the Fabric of Imaginem, surely.
Here's what happen when you post quickly at work... Extra botch dices!
Good plan. 
However it's an Imaginem Effect of a magic item (the Ship) that has been activated, not a spell. Does unravelling still work? Yep, but he might just activate it again before you can tell him not to?
cj x
Exercise 5: The Hungry Grog Really quick one today as I have to dash out. You are out on an expedition when Horace the Hungry a noted and valuable grog of your covenant happens across a rook of vis (ten pawns) in the form of a rather large and succulent strawberry. He only has time to chew once before you notice - but too late, Horace has swallowed the vis. How do you recover it?
cj x
Pissed of, I PeHe the floor under the fool*, let him fall to his doom 
- Ok, I'll need a finesse roll for this one. And I'll have some problems with the quaesitores
I think that with a generous applyance of CrHe you can put flour on everything in the whole structure. Then, with a slight CrIg you can have a nice dust explosion. This may not be what you want, but the opportunity is there, so you'd almost have to blow it up.
Strip Horace naked from the waist up.
Make him incline forward.
MuCo spell to open a hole in his body that is not mortal and take the vis.
Plan B: ReCo to make him puke.
Plan C: ReVi(Co,He) the vis into a new container (a nail of horace). Extract the nail of the bastard painfully to remind him that he should not do that. he will survive, but will remember the event for a while.
Plan D: kill horace. Search his entrails. You can always get a new "valuable grog" in the next town.
Xavi
ReCo to force him to throw up