Is there a way to add damage effects?

[Noisy Pants]

I've tried many ways and failed every time, so now I'm posting this as a discussion for those who want to talk about adding damage effects, such as: corrosion, blessedmetal, bleed, slow, to custom blocks. I tried making this "Tar Trap":

https://drive.google.com/file/d/1-K492ez_d01_kSVnYhdCZcy9acKd0iSM/view?usp=sharing

I'm having trouble adding any kind of damage effect to it, any ideas on how to do this and/or make it easier? Oh, here is a picture of me testing it:

 

[Knasp]

Have you looked at the code for the campfire and barbed wire blocks?

I think you should be able to apply damage by adding a buff, that is applied to the entity when it walks on your block.