Personally, I don't think that the use of linaments is 100% necessary for makiwara training, iron palm, etc. Understand that at the time, linaments were the only medicine available. Ice and warm heat can be obtained from many sources.
If you think it will somehow make your practice better, I would stick with more modern methods of recuperation. However, if you are more interested in the history of it, then try to find a practitioner of Chinese Medicine, as he or she would have more complete knowledge on the subject of healing with herbs and linaments than most MA teachers.
Glenn R. Manry
---Iaijutsu, don't forget the doorman.