[Cob] Oils for finishing cob/plaster/wood

[Rodger Chenoweth]

Hi folks.

Can anyone comment on why linseed oil is always touted as the best  
for finishing earthen floors etc.?  I know it's used for wood too...
Is it cost, availability, suitability, etc....?

I was wondering if it was possible to use any vegetable oil to finish...

1. earthen floors
2. earthen plasters
3. wood finishes

any comments are very much appreciated.

Cheers
Rodger