Why does my report sometimes have factors that slow or speed up genes, like COMT and CYP1A2, but other genes only have factors that clean and dirty them?

The genes that show factors that slow or speed them up, such as COMT, are somewhat special cases: the SNPs are very common, and each allele has benefits and risk. Knowing what factors can influence speed can be clinically relevant and useful. For example, if COMT is slow, that could be good for focus and attention but not ideal for estrogen clearing or falling asleep. So knowing how to speed it up to help clear out estrogen or fall asleep is handy as is knowing how to slow it down for increasing focus and attention. Genetic expression is modifiable through your actions. Having an understanding of your genes respond to your actions is important.
Meanwhile, In most of the other SNPs, having a variant allele may be a disadvantage. For example, a slow CAT may predispose someone to more oxidative stress. There are compounds which help speed up a slow CAT. This may then help reduce oxidative stress. Two compounds, garlic and polyaromatic hydrocarbons from smoke, are both known to increase a slow CAT. Obviously, we don't want to recommend you smoke to speed up a slow CAT. Therefore, we arrange these factors into categories that help/enhance/clean gene function and hinder/dirties gene function.