This is actually a non-oils suggestion, but maybe worth consideration?
In a small room, with possible budget limitations, I'd skip oils, and
go with acrylics= I've never found any of the big art colleges critical
of a portfolio that uses them over oils.
You can still teach techniques like blending, sgraffito, glazing,
etc, but without turpentine which really should be skipped unless
you have a great ventilation system. Also, think 'green'............
these toxic oil clean-ups should not be going down the drain.
Save yourself the fumes, limited storage, and expense of oils-
even "water base" oils are expensive.
In my small art room storage is very limited, , so I go with canvas board, and
slide them into one of the wire storage racks--which are inexpensive,
(tabletop) and can hold 100-- yes, they stick out a bit, but the stiffness
of the canvas board keeps them supported. If you really want them to have
the canvas-stretching experience, you might do a demo, and then make a group work
for the hallway. Or donate it to the hospital ( great PR).
Buying your acrylics in 1/2 gallon pump containers, ( SAX) and limiting the colors
to the basics, forces the kids to learn how to mix colors, and is very
You can spend two classes learning how many greens they can mix ( without green paint).
(A great prompt for a painting would be to paint a Rousseau- jungle ). Remind them he never
saw a jungle--so encourage them to make their own fantasy, but with MANY greens!
Oils are wonderful and "impressive", but the administration might appreciate
your "green" awareness, as well as not exposing kids to the fumes-
so often we work with kids in small, poorly vented
spaces- we need to make the right decisions about their safety--
even with small budgets.
If you still feel you need to offer an oil experience, I'd wait till warm
weather, and paint outside. You can also add a drying agent to the paint.