Yes, definitely - I won’t touch it!
Then again I may be the original poster who said this, so backing up my own argument probably doesn’t really count.
Echinacea is purportedly immune boosting. People with MS don’t have a weakened immune system, and if anything should avoid pumping it up.
If you are talking ONLY about homeopathic remedies, my personal belief is that as they are diluted to the extent of having NO active ingredient, they will neither help nor harm you. So I suppose it couldn’t hurt to take a homeopathic preparation of echinacea. In my opinion, you’d be wasting your time and money, but if you sincerely believe in it, I suppose you might get some benefit from the placebo effect.
Then again, if you really believe it does do something, you would presumably believe it is revving up your immune system, and that would not be a good thing for MS, so would the hope of benefit outweigh the worry that you might be doing harm?
For something as short-term as a cold, which usually only lasts a few days anyway, I definitely wouldn’t think it’s worth dabbling with anything that even might give the MS a little boost.
If it were me, I’d stick to paracetamol, and the most adventurous DIY remedy I’d try would be rum-and-black, which, as far as I know, isn’t contraindicated with MS.
Hope you feel better soon.