It's entirely based on your minimum MP - you can wash as many times as you want, as long as you have more than that amount of MP.
With a ZHelm you tend to gain 6-8 MP per level, which is about 3 washes every 4 levels once you've hit the minimum in the first place.
30k hp (base) by 200 requires ~355 points in HP (thus 355 AP resets), so you'd need to wash ~1400 MP by level 200, which would definitely need int equipment past what good warrior gear already adds.
In order to spend 355 AP without resetting back and forth, you'd need to start washing before level 130, and do 5 points every level. (starting with a normal lv.100 warrior, this means your gear needs to add about 180 int by every levelup from 120+)
30k hp (with HB) by 200 requires ~115 points in HP, so only about 460 MP washed. This would need int gear, but a Zakum Helmet + scrolled HT necklace would probably be enough as long as you got them pretty early (say 80 for ZHelm, 160 for Necklace)
The only real limit on how much you can wash is how much int gear you wear - if you've worn the same gear, you can wash the hp at any level as long as you have AP to spend in it.
With a ZHelm you tend to gain 6-8 MP per level, which is about 3 washes every 4 levels once you've hit the minimum in the first place.
30k hp (base) by 200 requires ~355 points in HP (thus 355 AP resets), so you'd need to wash ~1400 MP by level 200, which would definitely need int equipment past what good warrior gear already adds.
In order to spend 355 AP without resetting back and forth, you'd need to start washing before level 130, and do 5 points every level. (starting with a normal lv.100 warrior, this means your gear needs to add about 180 int by every levelup from 120+)
30k hp (with HB) by 200 requires ~115 points in HP, so only about 460 MP washed. This would need int gear, but a Zakum Helmet + scrolled HT necklace would probably be enough as long as you got them pretty early (say 80 for ZHelm, 160 for Necklace)
The only real limit on how much you can wash is how much int gear you wear - if you've worn the same gear, you can wash the hp at any level as long as you have AP to spend in it.