Well I am just looking into this 7-10 rule and don't know much about it.
In response to your silver question the rule does not talk about how long or deep the reversal may be. It does mention that for a change in trend it would be nice to see a limit down day or a gap. Looking at the April 7-10 days up and then the extreme sell off I would say the reversal ended. Also in the fairly recent 7-10 day move up to about 44+ to the sell off at 38.80 I would think that reversal is over. This reversal I did not see any gaps either. In summary it looks like the reversals are over, but I do not know how to determine that. Let me know what you think. We still have not broken one of the long term trend lines in silver.
In looking at the move in silver to 50 back in April it appeared to be a runaway move to me much like coffee. Maybe its best used to tighten stops or looking to take some profits.