I'm sorry I cannot answer your question directly, as I usually have a long soak in the bath each morning and I DON'T WEAR A BAG for this. It may sound like a 'risky' business, but in practice I have only had a couple of occasions in about twenty years where I've had output during this process. Even then, it was easier to clean up than a leaky bag. So, I CONTINUE WITH THE BATHING, AND ENJOY THE EXPERIENCE. For me, living with a stoma should not mean that we cannot enjoy life and try to carry on with what we want to do without the stoma dictating otherwise.
I am a firm believer in experimenting to see what we can get away with and what we would be well-advised to avoid. We are all different, so this is a process of personal trial and (sometimes) error. I tend to keep count of the number of times I get away with stuff and compare it with the number of times things go wrong. This gives me confidence because invariably nothing untoward happens most of the time. However, sometimes things go wrong when I AM NOT DOING ANYTHING 'RISKY'! So, who's to say whether taking risks is any more 'risky' than living what people euphemistically call 'a normal life'.