Old school way was Boiled linseed oil $11 @ bunnings 50/50 with turps $ 6 @ woollies Remove the action and rub all with a cloth wet with mix let dry do that about to six times water wont get to the wood .
Now days they will tell you there are better compounds to cover the wood in (
https://shop.birchwoodcasey.com/product ... h-kit.html) but if you look up whats in Tru-Oil' is made from a mixture of 56% mineral paint thinners( turps), 33% oil varnish and 11% linseed or Tung oil. The exact specification of the components are, of course, a trade secret (I dont wish to add the varnish to change the colour of the timber )
Tung oil or China wood oil is a drying oil obtained by pressing the seed from the nut of the tung tree. Tung oil hardens upon exposure to air, and the resulting coating is transparent and has a deep, almost wet look.
Linseed oil, also known as flax seed oil or flax oil, is a colorless to yellowish oil obtained from the dried, ripened seeds of the flax plant (Linum usitatissimum). The oil is obtained by pressing, sometimes followed by solvent extraction. Linseed oil is a drying oil, meaning it can polymerize into a solid form.
So real the difference is the cost for the same cost as casey,s 10ml you can make a litre of homemade .
Its up to you