a skindiver you can't really go wrong
The Forte stuff is really only meant to help keep the turbo clean though, it probably wont fix a sludged up turbo
You want a proper three stage cleaning kit like the one from Innotech, others are available
You can get it from ebay, now for £39.95 inc p&p (was £33)
It's a proper harsh chemical cleaner that works, steer clear of any with water in the product (it's not good for metallic turbos)
Will take 2-4 hours to do but is well worth the effort
Hope this is of some help DDD.
) SOLD I've sorted the airbag light 
run's for cover