I agree with Donald here.
Basically, you use DBs/barbells like you would curls for high level athletes or BBers -- to bring up weak links or something specific like that.
Otherwise, you're better off practicing movements that are more similar to the movements you are trying to accomplish. Aka bodyweight work.
If you don't have access to rings or something then sure go for it. Something that is a decent substitute will be effective and may even let you progress some without having access to the proper equipment.