I was never a fan of soaking logs. It's a bunch of work and will inevitably damage the bark, which will decrease the lifespan of the log. I always found it much better to let the logs fruit 'naturally' when the weather conditions permit it.
I would especially reconsider soaking them before their first flush. You may think they are close to fruiting now, but this is very hard to predict.
You could certainly transfer pathogens from log to log by using the same water.
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