Larry I have had RVs that had the pump fluid thru. They had a valve inside the RV with a extra tube. Sit a 1 gal RV anti freeze on the floor. Connect the tube, turn the valve than the water pump on. I liked that way. But, the blow out way is OK also. As I found out. It takes 2 persons. As you blow the lines, the other person needs to open the toilet flush valve. If not water stays in it. It is made to crack and fail at any freeze. About 40 bucks for a new one. Easy to replace but, just opening that valve to blow water out will prevent the crack. That should also clear out all water from the toilet.
2013 24RKSWE (27ft TT) Cougar 1/2 ton series
2013 Ford F350 4x4 CC 6.7 engine, 8 ft bed 3.55 rear end lariat package
Retired from Oregon State Police in 2011 than worked another 9.5 years as a small town traffic cop:
As of 05-2020, I am all done with 39 years total police work. No more uniforms for me.