
Avoidance of intrusive thoughts or triggering stimuli can actually exacerbate OCD. It's also not sustainable.
Even just a simple, "I'm sorry you are struggling right now. I believe in you," is so much more helpful and compassionate.
Remember that if you are supporting a loved one with OCD, it is not your job to "fix" them. Instead, your compassionate, non-reassuring and non-accommodating encouragement will help them more than any advice or correction.