There is still another option;
Innotec’s Turbo Clean.
What is it, what does it do?
You get a set of 3 chemicals, the cleaner, a neutraliser and an injector cleaner.
First, you have to take the exhaust pipe off the turbo (3 bolts).
Cut a cardboard blanking plate to fit in its place.
Now you fill the Turbo with the cleaner and wait @ 2 hours.
Drain the cleaner and run the neutraliser true, refit the exhaust pipe.
Pure the injector cleaner into your tank and go for a spin…
This set is designed for garages; I have never tried it myself.
Cost was @ £38 last time I checked.
As Gary mentioned before; Garret does not approve of Turbo reconditioning.
Still, if you have stuck vanes on your VW Golf, VAG will sell you a new turbo.
If you have stuck vanes on your Skoda (same engine, same turbo), the Skoda main dealer will take the turbo out and clean it!
Many Turbo parts come from China these days; they sell complete “Core” kits.
As always, some kits are better, some are crap.
Some skimp on the Nickel content of the Turbo wheels, which can lead to stretching of the Blades believe it or not.
Theoretically, you could build your own upgraded Turbo by using bigger Inducers as example.
Some US guys run their 2.4 JTD with @ 300 bhp as their daily driver with no problems.
A few things I noticed when I cleaned my own turbo;
The Vanes themselves seam to bind on their base plate (the Ring they sit on).
Just cleaning them with some Carb cleaner does not solve the problem.
I have polished the ring with 1200er wet and dry to get them working smoothly.
As always, the more effort you put in, the better the result.
all the best