Eliminating established weeds in pots

[mydogmimi]

Thanks to all who replied to my question.
I realized that Round up works through the leaf not if the soil. I suppose I could mix up a weaker solution a apply to one less desirable plant and see how it goes. My concern not so much the contact with pseudobulbs as the roots that have a covering of velamen that would absorb and hold this product.
Ill keep you all posted as to how my "sacrificial" plant fared. If it works, I will share the concentration and the details.