I use this concoction.
1 part regency grade isoprophyl alcohol
4 parts triple distilled water
3 drops Triton X114 surfacant
1 tablespoon Brillianze
Regency grade alcohol is available special order from a pharmacist that I know. My wife works in the medical field and has connections. The stuff is expensive at $28US for one US gallon. It is 99% pure. Lab grade would work fine, although it is slightly less pure, but the pharmacist cannot get that from his supplier.
Triple distilled water is available at any grocer in the US for a very cheap price. I don't know about its availability in the UK or Europe.
Triton X114 is extremely expensive, but I acquired a small amount which will last forever. A guy on eBay sells it.
Brillianze is commonly used in the copier industry. A copier service department should be willing to sell you a bottle. It is reasonably priced. I use it to control static. There has been some controversy about this product. I think that is because I thought of the application first.
I would avoid the use of naptha.