Does hp wash not apply to beginners?

It is very well possible to get the same MP gain if the difference is only 10 INT.

 

Your MP gain as a Beginner is between 10-12 points per level IIRC, plus a guaranteed extra point for every 10 INT. Each wash requires 8 excess MP, and the minimum MP formula for a Beginner is equal to 10L + 2, L = level. So at level 50, your MP floor is 502, meaning if your base MP is 568, you have 66 extra MP, enough for 8 washes. With your 20 INT base at the moment, you guarantee a wash every 4 levels. Each AP added to a Beginner's HP is worth 8-12 HP, while they gain 12-16 HP upon level up.

To be honest, I never found HP washing to be worth it on a Beginner save for getting a Zakum Helmet. It takes a ton of funds or adding INT which will cripple an already off the charts weak novelty class, and getting enough NX to remove the INT later will be a very time consuming thing. For an idea, at 70 in GMS, I think with a 101 attack White Mop, my range was only like 2xx-18xx. Other than that, I feel that it's a waste. If I was to wash a character, I'd do it for a Bowman or Thief. And even if you did have about 3k HP on your level 100 Beginner, you still can't train with other level 100s, since even if you could hit those high level enemies, it'll take ages to kill them and you'll burn pots like mad.

Most of my knowledge about this is from a Beginner I knew from another server that has a level 100 Beginner with just under 2.8k HP (note that average HP for a level 100 Beginner is only around 1.4k-1.5k). Hope this helps.

In summary, yes Beginners CAN HP wash, but in my humble opinion it's a waste.