I messed up my Epson 860 printer by in stalling a color cartridge
bought from the webside "ink boulevard" and I would appreciate if
anybody can give me some advice how to unclog the ink delivery
channels which are apparently causing the problem. Please don't refer
me to webside www.fixyourowncomputer.com since I tried this already.

At first these ultra cheap cartridges were satisfactory. Later they
did not work but by drilling holes in the cartridge and adding some of
the liquid supplied by www.fixyourcomputer.com, partially fixed the
problem and adding more fixed it completely. This time this does not
work. I bought some expensive ($ 58 for black and colored) cartridges
but am afraid to install them since if the printer is damaged beyond
repair I would waste these expensive cartridges too. I have 4 options:
Either install the last  "ink Boulevard" cartridge as is, or install
it after adding some of the above liquid, or install the expensive
cartridge, or buy a new (preferably refurbished) Epson Stylus Color
860 and return the expensive cartridge

Please advise me what is best to do.

At the current price of inkjet printers (20 bucks or less) I'd buy a
new printer and send the stuff back