I've heard of people using Scotch Guard to lock-in the shine on hair and repel water etc.
Someone on another forum has suggested a spray teflon to do the same thing.

Putting oils on your hair a night is all well and good, but saturates your pillow cases in gunk and then rubs off on your face during the night.
Can be really bad for your skin.

There is an oil in most of the glue removing solvents, often in the form of essences that perfume the product.
Thats why you need to thoroughly wash off those solvents, so that the oils don't prevent a secure attachment when re gluing.

Its a great concept to attempt to nourish the hair from the inside, but on the whole impractical with replacement hair.
Its probably better to go for the appearance of nourished hair by using one of the many 'shine' sprays available, that simply coat the hair.