No, don't do that. The OP says that "...they don't open at all, or open unevenly..." which indicates there is probably more wrong than thickened lubricant. Possibly the blades are not engaging properly with the actuating ring, or something was damaged by drag caused by the thickened lubricant.
Originally Posted by MDR
Do it right, do it once, have a reliable shutter... try home made half-baked repairs and have potential junk. This shutter is nearer 50 than 40 years of age at a minimum, possibly it has never been serviced.