You should really disassemble the timer mechanism and clean off the old gummed up oil and re-oil. The problem with using any solvent be it alcohol or lighter fluid is the dissolved oil has to go somewhere. And when the solvent evaporates the old oil will gum up again. The excess and vapors from the solvent could also cause damage to parts and materials in the camera. Alcohol will react to more materials (rubbers, adhesives, coatings, thread lock etc.) than lighter fluid.
You should use a gumming resistant oil such as a fine clock or watch oil. Some repair sites say you can use sewing machine oil.
What camera is in question? You may be able to find a service manual or youtube video online to guide you through disassembling the relevant parts.
This video shows repair for a worn timer on a Nikon F. Although it may not be your model of camera it will give you some idea of what tools are needed and how to access the timer mechanism.