What solvent can I use to clean a Canon (LP2000 detachable) print head?

Isopropyl alcohol is the best. Ideally, you could use the anhydrous form, but 90% should be available at your pharmacy (chemist). Stay away from anything lower like the commonly available 70%.

"DO NOT use alcohol OR BLEACH!! Either of these will destroy the print head! Distilled water is the best and easiest to obtain. Each printer manufacturer
uses their own formula, when they develop their ink - IF and only if, you can
find out what cleaning-type solvent they use in their ink, you could use that. It
Is unlikely that, even if you can find this out, you would readily find it available -
if at all. The person who used alcohol, that's what destroyed your print head(s).
Bleach would only expidite the destruction. I, too, have purchased a brand new
machine, in lieu of new ink! Simply because, at the time, it was cheaper to do so."

"To make printer cleaning fluid, the thing you need to do is very simple, namely by mixing clothing bleach with plain water with a ratio of 1: 1 in terms of 50% water and 50% clothing bleach (half-half). For the amount needed, you can set it yourself according to what you need.

Try to mix the two ingredients evenly, after the cleaning fluid has been successfully made you can immediately use the liquid to clean your dirty and perturbed printer head."