I think the main reason the recipies call for diethyl ether is that it is the solvent used to make colloidion. Used in a well ventilated area, well away from flames or sparks, diethyl ether is not to bad to work with. Under any other conditions, it's an extreme hazard. It is particularly a fire hazard, and warm objects or sparks you normally may not even be aware of can set it off and burn the house down. The vapor also tends to sink and crawl along the floor - beware the water heater. You can certainly experiment with other solvents. Most that might be suitable (like somewhat higher ethers) are also quite volatile and flamable. Remember that one of the qualities you need in the solvent is pretty good volatility. My recollection (and a bit of experience recently with label removers) is that amyl acetate is likely to leave things gooey. Ethyl acetate may work (that's just a guess). MTBE may work. Tetrahyrofuran may work.