Cleaning fuel tanks?

[copout]

Here's what I got!
One polly tank below deck.
One aluminum tank above deck but below console.
Neither can be removed without major mods.
I have removed all fuel. The bottom tank was BAD, tar/varnish residue on the bottom.

Plan of attack!?!
Flush with water/degreaser?
Flush with staight water.
Remove water.
Rinse with Iso-alcohol, them pump that out & then vent/run blower to evap remaining Iso?
Complete with new lines, spliter valve & hardware.
I am open to suggestions.


Top tank



Bottom tank