A pool is really just a layer 3/4 path to a service and has nothing to do with URIs. If you've disabled all of the members of the pool, then you shouldn't be getting to the application.
The HTTP::uri command simply changes the URI in the request as it passes through the proxy to the pool. The client doesn't see it.
The HTTP::redirect command issues an immediate 302 redirect response to the client. The Location header in this response tells the client to make a new request to the specified URL. If you issue a redirect in the iRule, traffic will not pass to the pool.