My understanding of the best way to maintain an oil finish is to mix boiled linseed oil and turpentine (say 80% BLO to 20% Turp.) and put a drop on the stock, rub in, leave for an hour and then buff the stock with a soft cloth. After a day or two, apply renaissance microcrystalline wax polish.
This method should do no harm and I use it on all my english guns with traditional oil finishes.