Mom with dementia had 2nd stroke that affected her left side. Any way to lessen the drooling?

Seek out the answer through her neurologist.

Keep in mind this is not the mother you knew in years pass.  This is mother that is acting like a child because of her mine, which she has very little control of her.  Be understand and make sure everything is in place so you mom will be well taken care of.  Everyday when something negative happen, just think, would you get upset child if they were acting like that.  If it was your child, you would still be  understanding and loving.  This is the reverse roll we have to play as long as we can.  Be encourage and God Bless you.

A friend of mine had a daughter that did that alot: They went to the doctor and he put her on meds for it. It helped considerably.

Neurologist will have answers. That entire left side of her body is effected. Although sometimes worthless, a "speech therapist" might be able to help, since that entire side needs to relearn how to do everything. Getting her up and moving, via a physical therapist, will help alleviate the issue. When that left side becomes tense through what they term as "uncontrolled tone" the drooling might get worse; which standing helps eliminate; the leg due to weight bearing, usually comes back earlier than the other regions of the affected (in this case-left) side. All in all consult her Neurologist, for more specific, patient specific MRI/CT imaged based answers.

So, yes, you should talk her doctor about this.

Im reading on your profile that you are the sole caregiver for your mom with no adult day care available? And that you don't want her placed in a NH because all her assets will be taken from her?

I'm not sure what to make of that. Can you pay for respite care from mom's income ( social security?) Have you looked into applying for a Medicaid program that will provide some in hkme aides?

She should have a swallowing test done
other suggestions (if is really bad) is Botox injection in the salivary gland but then you would have to keep her mouth moist enough to swallow
if it is slight you could try Atrophine eye drops one drop twice a day

If your mother had the second stroke six months ago... Has there been an increase recently that's led you to ask about it now? If there has been a marked change, I should report it to her doctor. It may be that there's a problem with swallowing.

I haven't checked your profile - how are you and how is your mother coping overall?