The leaves will get spots if you splash large drops of the solution on, but a nice fine mist should be ok. You need to cover the mealy bugs with the spray.
I understand what you mean about the plants looking like mushrooms. They get a long stem over time as the lower leaves die off. You can either start new plants from leaves or cut the stem off when you repot. Here's how from Buffalo Violets at GW.
Scrape the neck with a sharp blade or your fingernail to expose the tissue underneath. Dust the neck lightly with rooting hormone. You must now "bury" the neck in the soil. You will probably have to cut off some (or even all) of the rootball. DonÃ¢â‚¬â„¢t worry. The buried and scraped portion of the neck will produce new root.
Your plant now needs to spend all its energy on new roots so remove any blossoms. To prevent the plant from wilting or going into shock from losing part of its root system, place the plant under a dome or inside a Zip Lock bag to create added humidity. This acts like an ICU.
Keep it out of direct sunlight but in a bright spot. Here's a helpful site.
Here's sites that show how to propagate. Look at the two different types of leaf cuttings at this first site to propagate new plants for your African violets.