[Amps] Is cleanliness next to God-liness?

[Frank N. Haas]

Fellow AMPers:

I just took delivery of 3 well used 3CX400A7/8874 ceramic power triodes. I 
bought them as spares for my recently purchased Alpha 78 amp.

All 3 tubes are rather tarnished with many dark spots and no shine whatsoever.

I want to test these tubes in my Alpha 78 to insure that all 3 work.

Should I clean them before I install them??? If so, what is the recommended 
cleaning technique for these tubes?

Are common "household" products like TARN-X, NEVR-DULL, BRASSO or the like 
appropriate??

Is it even important that the tubes be clean?

73,

Frank N. Haas KB4T
Florida