Khaki...it's true plants can go in shock when roots are disturbed, (and many other reasons) but if you're careful, you can remove plant from container, toss old soil, and wash roots clean without harm.
I believe some people make a mountain out of a mole hill. They make it sound if a root is touched, the entire plant will die..NOT so.
IMO, people who can't keep their hands off a seedling or cutting, 'to check if roots formed,' have a much better chance of killing their baby. I know people who can't resist checking a rooting cutting. I tell them, 'let the cutting/seedling be.' The baby dies, and they wonder, 'what happened?' lol. But an established plant is a lot hardier than a seedling/cutting..If you're careful, no harm will come to your plants.

I've washed entire plants including roots on many occassions...especially after purchasing a plant and found insects or when soil was drenched and needed fresh.

The easiest way to clean roots is by bringing the plant/s outside, remove from pot, and hose off old soil and insects.. If you're going to reuse the pot, it too should be cleaned w/soapy water.

Ficus don't like change, but RT's are hardier than their cousin, F. Beji.
Think of it this way. If there's insects eating roots, isn't it better to wash them off then allowing them to stay in the soil??

I've read cent/milipedes eat roots, but 'supposedly' not enough to kill a plant..but if your plant is infested w/these creepy crawlers, and each eat a piece of root, eventually there won't be any roots left..no roots no plant.

BTW, did you see bugs in your Rubber Tree soil, too? If not, and you just want to repot, there's no reason to remove soil from roots.

After hosing the plant w/Centipedes, pot in fresh soil. A well-draining soil. Water thoroughly with room temp water. Place in its normal spot.
BTW, what type of plant is it? The plant w/centipedes..yuck. lol.

Good luck, keep us posted..Toni

I've never heard of centipedes being a problem for plants. I always thought centipedes ate other bugs, not plant matter. Anyways, completely washing plant roots, as said, can be done without much harm. The big thing to remember is that they are plants, not animals....they have no brain. They don't go into shock because of the experience, but because of something that changed, or happened. For example, if you handle the roots too rough, you can damage the fine little hairs that actually do the water absorption. If you damage them, the plant cannot sufficiently take water in, and has to repair itself, and in response will drop leaves. You can also damage cells by using cold water, which will cause shock also.

As for how I've done root washing, well, I use a bucket of room temperature water, and gently swish the rootball around. If necessary, I'll coax the soil off of the roots with my hand, but VERY gentle. I can't over-emphasize the word GENTLE, because you have to minimize damage to the roots. If you have soil bugs, you absolutely HAVE to remove it all, or risk leaving bugs, or eggs, in the roots to reinfest you plant. Good luck!

If you can remove all of the previous soil from the root ball of a plant when re-potting, you should. It's better to have all fresh medium within the container, including around the roots, so the medium will absorb and release moisture evenly when you water.

There's much less chance of shock or stress if you keep the roots moistened and out of direct sun or wind while working with them. Using tepid water also helps.

Once the plant is safely ensconced in its new home with fresh, new medium, it's best to keep it out of direct sun or wind for a little while... until the roots acclimate to their new surrounding soil. Keep it protected for a week or so, then gradually move it back to its home.

Roots aren't as fragile as we sometimes think, though there are plant types that are more sensitive to change and stress. But if we handle them with care, and follow a few simple ideas... like keeping them moist and out of sun or wind... they should do just fine.