Re: Any tips on dealing with reducing DSLR macro-blocking artifacts?

There's very little you can do, but have a look at Graeme Nattress' plug-ins for Color. Depending on where the macro-blocking is worst (which color channel, which luminance region) some clever masking and smoothing may improve the picture without making it too soft.

But basically everybody around here is right: "Aus Scheiße kann man kein Gold machen" as we say in German (I suppose you understand and hope it doesn't sound too rude). The last ones who tried were the alchemists…