I'm not sure what you mean by "conditioner" b/c many different products are called by that term. Some are useful or even essential, and some are a waste of money. CYA is sometimes called a "conditioner," tho, and it is a necessity for outdoor pools!
Clarifier is generally not recommended on this forum. Most folks, I believe, consider it an unnecessary expense. I think it's Waterbear who says, "A clarifier can clear up your water in seven days; filtration may take a week."
The BBB method and this forum are all about keeping one's pool sparkling using simple methods and inexpensive products. Many of the expensive specialty chemicals are unnecessary or needed only in special cases.