I use my toppings as clones all the time. It takes a little longer for them to get established, but it will work.
I cut my stem at an angle under water (as recommended by another thread), then use rooting gel & stick it in a rapid rooter. You can go right into soil, but I like the contact the rooting plug makes with the stem.
Consider using a humidity dome (old water bottle top?). I keep the soil moist, but try not to mist the leaves. I want it to develop roots & get its water this way! Spray the inside of your humidity dome.