funny subject
Never paid any attention to brands... crochet thread would probably be the cheapest, I guess...
Now, a step further... have always tied a double knot in the center of the thread, to pull through the wider spaces at the gum line.
A bit off topic, but food for thought... after years of spending today's equivalent of $70 for cleaning, found a good set of dental tools for scraping/picking, and did my own cleaning. In the beginning, used a mirror, but now can do most of it by feel. Yeah... am that cheap! And, haircuts too... total cost over 58 years... four Wahl clippers. Hmmm... @ $15/cut (including travel cost and tip) once a month... = 12X15X58 or $10,440.
Frugal? Uh huh!... Now... colonoscopies.... Lessee... one every 3 years @ $1700 = ..............
Where did you get the dental tools?