Well I have 3 bettas and I do a complete water change every week!
I do not use a hose as their containers are too small.
I saved the little cup that they came with.
I pour the water over a big bucket and catch the betta in the cup.
Then I dump the rest of the water in a stainer as I have colored glass rocks in it.
You only have a few bigger rocks so you could remove those before you pour the betta in the cup.
Then I rinse out the bettas bowl and refill it with the same temp water as was in the bowl.
Add my plant and stones. Fill with water and add Betta Plus bowl conditioner to the water by Aqueon.
Lastly I pour the betta into his clean bowl, gently!
Netting a betta is too stressful everytime you clean the bowl.
My one betta is over 2 years old now. I have always cleaned their bowls this way.