Well, that's what the Flic-Film Black, White, and Green film developer is intended to be -- i.e. a commercially available pre-mixed PC-TEA. And PC-TEA, in turn, was intended to be a long-lasting, liquid concentrate equivalent to XTOL.
The Flic Film developer is made in Canada, but is available from at least one U.S.-based retailer: Photo Warehouse, who calls it "Ultrafine Black, White, and Green" on their website. (Photos and the full description show that it's the Flic Film stuff.) I just ordered some from them, and they shipped it to me yesterday. Total with shipping was $34.90. You can find it here:
A very ECO (environmentally) friendly developer that can safely be flushed down the drain or into your septic system without guilt or harm. The active developer is Vitamin C and the superadditive is Phenidone, long known as a low toxin developer. The developers are carried in an alkaline...
www.ultrafineonline.com
I haven't used this developer before, so can't give you any feedback on how it works. I do agree with others that if you're just starting out, you may want to begin with a very widely used developer known to give good results across a range of conditions.
When I first started developing film again (after a 30-year hiatus), I began with XTOL. It gave me very good results, but mixing it from powder, in 5 liter quantities, and then trying to keep it from
degrading before I had a chance to use it (I don't develop that much film and certainly not on a regular cadence) became a little inconvenient. That's why I'm interested in trying this liquid from Flic Film; if it looks good, and doesn't degrade much over 12-24 months, it could be the right stuff for me.