is it bad to wash your ponies?

[faespirit]

So I heard from somewhere that running your ponies under water can cause problems like tail rust and icky mold. I wash my ponies—a LOT (mostly to keep them clean) and every time I do so I kinda feel guilty because there must be a lot going on inside them without me even knowing.

[goddessofpeep]

It is possible to wash ponies without causing problems, but water can easily cause mold and/or tail rust, especially if exposure is frequent or extended. The risks depend on basically how quickly and how well you are able to dry out the pony afterwards.  If you submerge the pony, water is very likely to get inside through the tail hole.  It’s hard to get the water out without removing the head, and you’re likely to end up with tail rust or mold, or both.  Frequent washing, even surface washing, can encourage mold to grow if the pony doesn’t dry completely.  So can just humid air. 

If you are careful, you can reduce the risks. 
First, don’t submerge the pony unless you’re prepared to deal with water getting inside. 
Second, let the pony dry completely afterwards.  Some people remove the head to make sure the inside dries completely, though if you’re not good at popping heads off, I’d be careful.
Third, only wash the pony when necessary.   The more you expose the pony to water, the more chances you give mold to start.
Finally, keep the pony in a dry place.  Humidity is your enemy!   

[SpacePinto]

I was afraid to wash my ponies out of fear that I would ruin their eyes and symbols, now I'm glad I didn't Not that I'm never going to clean them, of course, but first I want to figure out how to do it safely.

[goddessofpeep]

It’s generally safe to wash normal painted symbols as long as you don’t use a Magic Eraser.  A Magic Eraser can take off pretty much any paint with just a few swipes, but a *very* light pass over a painted symbol with a Magic Eraser can be ok if you’re *super* careful.  If you’re really concerned, a paper towel or just the pads of your fingers should be perfectly safe.  Glitter symbols, Magic Message symbols, and other weird symbols require much more delicate care. 

[SpacePinto]

Do you think it's okay to stuck tissue paper around the tail base and then wash the body with a damp cloth or something?

[lovesbabysquirmy]

Don't soak them.  Let them dry thoroughly.  Don't scrub at symbols or paint.  Use hand soap or dish soap first, NOT anything stronger.

[Leave a Whisper]

No its not bad to wash them if they need washing.

[faespirit]

If you submerge the pony, water is very likely to get inside through the tail hole.  It’s hard to get the water out without removing the head, and you’re likely to end up with tail rust or mold, or both.  Frequent washing, even surface washing, can encourage mold to grow if the pony doesn’t dry completely.  So can just humid air.

I mean I guess that as long as I don't 'submerge' the pony in water it should be fine? Hopefully dunking their manes in a bowl of water and wiping them down wouldn't do anything.

[tailrustedtealeaf]

Yes, problems really only happen when water gets IN the pony. Wiping down is fine, wet manes are fine.
Both tail rust and mold can be fixed, at least.

[SunPony]

Like others have said, the key is keeping water out of the inside of the pony in the long-term, which is how mold and rust form.

If the pony has a loose head, I will wash them in a warm water and dish soap bath as needed, then dry the head and body separately and reattach when thoroughly dry.

If I have a dirty pony that still has a tightly-glued head, I try to clean her using just a damp Magic Eraser or a damp toothbrush with a bit of soap.  I keep a dry towel nearby and wipe the pony if any water starts to run over her body, so it doesn't run down to her tail. 

Then there is the problem of ponies that need their tails washed/conditioned, but have tight heads.     The tail will wick the water inside via capillary action.  The best I can do is try to keep the "butt end" of the tail as dry as possible to prevent this.