so glad you asked this, ive been inform how to do it much faster than in an oven and have been using the technique for a few weeks now.
i smoke a lot, so my grinder is always packed full of keif.
here is what you do...
fill your grinder with keif, i know i know it is hard not to toss some of that golden beauty on top of your bowl and smoke it but please refrain as the reward of waiting and saving it is great.
once you have saved a large amount, get the following materials out..
1 paper clip
piece of cardboard
1 dime bag (purchased at your local head shop, smallest size)
you need a stove top that doesnt have burners or use a frying pan if you have external coils.
fill your dime bag half way full with keif.
seal it and pack it and fold the bag in half and tape it with a tiny piece of scotch tape.
take your cardboard and cut it big enough to wrap around your folded dime bag.
moisten up the cardboard really good.
wrap it around your bag and put the paper clip on it to hold it shut and wrapped.
put your oven on medium heat and get a spatula.
toss it on the burner, shouldnt smoke. press and flip it maby five times.
run undre cold water to cool paper clip, pull it off and check to make sure the keif is hardened, should be grenish brown not dark or burned. this takes maby 5 min to do.
enjoy