Oil the dry recorder with a cleaning rod (fuzz-free cloth about 2 x 5 cm, insert through loop), polishing inside (and out, if the instrument is not lacquered!) but do not use an excessive amount. Please do not oil the tenon with cork.
Use almond oil or cold-pressed linseed oil. Be careful with the headpiece: oil inside only up to 2 cm before the block, oil the whole of the outside, but on the labium surface apply very carefully just a little oil at the front. No oil should get near the block! Stand the oiled recorder overnight on newspaper to dry, in such a way that the superfluous oil does not get into the finger-holes or onto the block. Wipe away any remaining oil the next day with a dry cloth.
If you are unsure, it is better not to apply enough oil than to use too much! Depending on the amount of use, oil the recorder once or twice a year inside and out! Oil takes care of and impregnates the wood, and the sound becomes fuller.