Is bio resonance therapy pretty effective for arthritis?

Effective 4 nothing. Bioresonance therapy is completely bogus. See http://www.quackwatch.com/01QuackeryRelatedTopics/Cancer/bioresonance.html.
In general no. Uncertain. In general no. This is electromagnetic therapy but has not had a role in sustaining effective therapy for arthritis. There are many types of therapy and much better therapies are available depending on the type.