[Cob] oil and cob

[Kim West]

Having read the last few posts about sealing cob I am wondering--if one 
were to put extra thick lime plaster [that doesn't have oil added to the 
mixture] on the outside window sills, could some applications of oil 
then be used after applying the plaster to help further seal them as 
long as it is only put on the top surface of the sills--or would putting 
oil on lime plaster be redundant?

And with linseed oil on a cob couch or bench--would not the oil get on 
your clothes?

thanks

k