Anyone had their frame blast cleaned with walnut shell or something equally gentle on delicate aluminium?

Commercial dip stripping has not worked as my frame appears to have been stove enamelled and when i tried manual stipping my last frame (from the same manufacturer), it took hours and hours. This frame has lots more welded seams with difficult to get at recesses.

Many blast cleaners use sand which is too abrasive. So I need to find a guy who knows what he is doing. Who has experience with decent aluminium bike frames.

Cheers!

I asked the same question the other day and am taking my Blur to the guys at Triple-S (google em) in Bingley. They work on motorbike restoration stuff mainly by the look of it but do know how to treat a bike frame judging by the conversation I had with them yesterday. They can arrange delivery/drop-off as well.