Like in medieval times when they only bathed few times a year.

Ah, this old chestnut. Bathing is a specialised form of personal hygiene that requires most probably a visit to a bath house. Boilers. Large quantities of hot water. Soaps, oils, the lot. But washing you can do basically anywhere there's water. And maybe soap. Most medieval settlements were situated near to rivers, and those that weren't had wells. And where you have water, you can wash. In Coroner's Rolls for Medieval England, a commonly occurring cause for accidental death is drowning in a river or lake while washing or doing laundry. So it seems likely from this fact alone that people were regularly washing themselves and their clothing in England's waterways throughout the Medieval period. For example, from the Bedfordshire coroner's roll of 1269, on the 24th of April:

And at the said hour John took off his clothes and entered a certain stream in the said yard to bathe, and he was drowned by misadventure

Similarly at Wadenhoe, Northamptonshire on the 31st July1301:

They say on their oath that Robert took a bath, so it is said , in a certain place called Forth in that stream and by misadventure was drowned ; and they say on their oath that they know nothing more.

Coroners Rolls even indicate that some people did have their own domestic baths, as in the case of one murder in which:

They say that William Chaplain hit Cecily Sabarn with the leg of a bath

People may not have washed as often as we do today in our modern germaphobic society, but personal hygiene would still have been a regular occurence.

People in an urban setting may nave actually just regularly visited a bathhouse which were common in most large and even some smaller cities throughout the Medieval period. Paris at one point had almost 30 bathhouses and a guild of bathhouse keepers, and London had an entire district ostensibly of bathhouses (although also extensively used for businesses of a less salubrious but equally naked nature). Many wealthy individuals likely enjoyed regular private baths: Goscelin's vita of Saint Eadgyth mentions how, while at Wilton, she insisted on naving a heated bathtub, which she regularly enjoyed (with an implication that fellow members of her community at Wilton often took less warm baths).

Remember as well that the majority of people's clothing would have been made of wool, a very versatile natural fabric which, among its many other qualities is regarded is being "self-cleaning", in particular capable of ridding itself of unpleasant smells if sufficiently aired out. On top of this, people may also have worn fragrances. Guy of Amiens in his Carmen de Hastingae Proelio recounts how the English, on the eve of the battle, spent much time combing their long hair and beards, and oiling them with perfumed oils so that they could look their best if they were to die.