Where to draw the line with Uchiko

[Utopianarian]

This may be considered Taboo. I may be criticized for this which is fine but wanted to be honest and open as many here may very well do the same thing which I stumbled on… I noted the fine effects of fine quality Uchiko. What I mean is I experimented with it by repeatedly applying as you would clean as sword in proper sword cleaning etiquette but ramped it up a bit to see what would happen on a lesser blade I own by using a very fine cloth and pressure with my thumb in essence rubbing the fine light Uchiko which was tapped over the blade repeatedly over a few weeks which greatly enhanced the detail of the blade in every way with very little metal removed. The blade was already moderately oxidized with scratches etc… would that be considered an act of an amateur polisher. If so where would one draw the line. 

[Brian]

Contentious issue.
But many of us (myself included) have settled on the theory that it's ok on completely out of polish blades...it will bring out the hamon a little bit) but NOT to be used on anything in semi decent or full polish. If your sword is in polish, DON'T use it, and stick with microfiber cloth and ethyl alcohol.

[Utopianarian]

Yes, Definitely I don’t touch or even use it on my polished blades or even very nice conditioned blades. I am in the same camp as many here to not use due to fine scratches which will be apparent on fine polished blades. I know it has been discussed many times here on the board but I don’t understand still why I’ve seen Masterwork blades already in polish being cleaned with Uchiko especially Top shelf blades by High end dealers and collectors including high level Former NTHK heads in Japan gradually eroding history. I guess tradition wins over preservation 

[Brian]

They use the highest quality of uchiko, unlikely to have any larger grains in it, and also know how to apply the correct pressure.
Many of them have changed over to modern methods, but I'm not going to tell them to avoid uchiko, it can have benefits but most Westerners don't know how to use it properly and it leads to hike/scratches.

[Jacques D.]

The uchiko is abrasive, its use on a polished sword will end by weaken the hadori. As long as that was all we had to clean our swords, we used it, but since the invention of the microfiber, it is no longer necessary. Personally, I have not oiled my blades for a long time, with a relative humidity of 40% to 50%, there is no need for it.  

[robinalexander]

For posterity.....adding a previous link for interest and information ....

https://www.militaria.co.za/nmb/topic/35804-uchiko-according-to-kojima-hiroshi/