i was told by my indi that cleaning will only help if they are clogged, but its the solenoids inside that wear out and cant keep up, he said if you get 100k out of them on a standard car you have been lucky, on a mapped car probably less, mine lasted 85k , if rtech is rebuilding them then i would do that, but wouldnt bother touching them unless they are causing issues, and when they do either rebuild them if you can, or replace, £200 each OUCH!!
thought mine were dear at £158 each