There is an art to kiln drying. Every species of wood drys differently. The whole idea to remove the moisture from the green (fresh cut) wood without cracking it. If you remove the moisture to quickly it will crack and loose it's integrity. If the cedar you are using was bought at a hardwood lumber yard or Lowe's, etc., it has been kilned dried.
If you went outside and cut the cedar off a tree before you turned it, it is very green. Green wood turns better than dried wood. But, it will warp as it dries. If you are turning it green, oversize it and let it air dry. Be patient, it takes 1 year per inch. In other words, if you cut down a mesquite tree, have it sliced into lumber at a mill 2 inches thick, it will be ready to use in two years if you have sticked it. Sticking means placing a dry piece of wood perpendicular to the green wood every few feet. The purpose of sticking is to let the air get to both sides of the green wood.
Putting the wood into your oven would be tricky. 150 degrees is the highest temp the green wood could take before cracking. It also would take about a week for your cedar plugs to dry. Putting wax on the end grain helps retard the drying process. It also keeps it from drying out to fast.
There are a lot of varieties of cedar. Western Cedar is the one you see going on fences. Lowe's and Home Depot sell western cedar. It is commonly used to trim out exterior door frames and facia trim along the roof rafters. It should be plenty dry for your plugs.