don't use thread lock on the plugs!! that stuff is meant to make a permanent bond.
thread them in by hand, then get a 3/8 breaker bar on them til you meet resistance. then give them a 1/4 - 1/3 turn to tighten them in
i had a vw before, some donkey had cross-threaded a plug in - had to get a new head (cost more than i paid for the car!)

 

There are different colors/strengths of thread locker, I think the red is like welding something and the blue isn't that bad, it has been a while since I have used either so don't quote me on it.

 

i work in a volvo dealership, they supply us with green thread lock - it will not budge when it sets (didn't know about the various colours!)
you still should not use thread lock on spark plugs - if you're gonna put anything on, use a little copper grease to make them easier to come out

 

There is thread lock for spark plugs, you can buy it at the autoparts store. I've put thread lock on plugs b4 but i've never had to take them off. I was working with a mechanic at the time and he said put the thread lock on. I'm pretty sure that the stuff they sell for spark plugs isn't that strong.

 

horses for courses i guess then!!

 

I have been changing my own plugs for almost 30 years now, this is the first time I've ever heard of anyone using thread lock on plugs. The reason a lot of books suggest starting plugs with a rubber hose is so that if the plug meets resistace going in, as in the case of cross-threading, then the hose will slip around the plug; thereby preventing someone from cross-threading the plug. I also follow the general rule of a 1/3 to 1/4 turn once the plug bottoms out, followed by a dab of dielectric grease on top of the plug or in the plug boot.