I usually replace the brush and its holder about every 5 or 6 months. I just add some more water and soap when it starts to get a little low. I haven't ever noticed any mold.
Same. I have very severe asthma and I use a regular brush as well and have never noticed an issue. I clean the toilet, make sure the fan is on and leave the bathroom to let it air out.
Now, I do admit, I usually do hold my breath for the minute or two it actually takes me to scrub the toilet but thats mainly because I can't stand the smell...lol (it really doesn't take very long). This was actually one of the (many) things I recently asked my allergist and pulmonologist about and they both said that I am in and out of the bathroom in less than 5 minutes when cleaning the toilet so they are definitely not concerned with what I use.
I put in the chemicals, leave the bathroom and let it sit for however long (10 mins i think), go back in, scrub the toilet (never takes very long at all), turn on the fan and leave the bathroom
But to each their own