Aquastore water tank

I have done much research, even emailed manufactures on what is the best way of cleaning these water tanks, the tanks are glass fused to steel (procelain enamel coating). its difficult to get any info on this, so far I found out no highly caustic or acidic so Im a little worried about using SH on it. Although for oxide streaks they did recommend a mild muriatic solution. Has anyone out there every cleaned one of these types of tanks before, and what would you recommend using? I will be x-jetting the solution on.
Thanks for any help!

Sounds interesting, do you have any pics?