Is it safe to use injector cleaner or will it clog something. Whats the best brand?

The best cleaner is a second fuel filter. Later! Frank

Barring the second filter. Has there been a problem with clogged injectors?
I know I am not totally sold on the idea that the second fuel filter is the best protection against injection failure. Seems like the failures get you no matter what.

Cleaning the injectors from time to time couldn't hurt could it?

Personal experience

Do not mix 2 different brands of fuel additive, I found that they will separate and leave a solid residue, it could be a wax deposite??? The thought here is if it separated in the filter could see some blockage.

good luck