HotSpring has a drain in the very bottom of the spa, which is a selling point.
BUT....
I use a large-diameter hose to syphon - it goes much faster and if you can be there the whole time, you can get the water out of the seats and filter bucket at the same time in one operation.
I have a 38" section of PVC pipe so that I can keep the suction-end of the rig on the floor of the spa or in the seats/filter area as needed. The end of the pipe goes into the end of a commercial 2" pool vac hose and it absolutely rips! In fact I have to move the loose end of the hose around the yard to avoid flooding. The pipe also keeps the thing where you put it if you want to step away to rinse a filter or move the other end of the hose, or if you just want to start the syphon and come back later.
Sounds complicated, but it is very simple and works like a charm.
I have seen folks buy cheaper pool hoses, sections of suction-type pool cleaner hose (comes in 3-4 foot lengths and snaps together) or even just a section of 1" vinyl tubing or what-have-you. Its all good, but keep in mind that when it comes to the speed,
Size matters.