The answer is "kinda" -- what this plugin does is essentially fake a form post to a third-party URL, mimicking the form that CRMs often provide for lead capture. So at a basic level, as long as you map fields correctly Salesforce thinks you're capturing leads with their form, which is "so simple" it's why there's no functional example.
Are you talking about a different integration point with Salesforce than their web-lead forms, like an API? If so, and it doesn't accept POST requests, you'd probably need to use the same CF7 hooks my plugin uses to make your custom remote request, meaning you might not really need my plugin.
If you're just trying to test the plugin response, you shouldn't need to var_dump anything. You should be able to turn on "debug mode" from the mappings screen -- this will send you (or whoever you've set as the debug email) an email containing the raw data from the CF7 form, the mappings, what's sent to the 3rdparty, and the raw response from that submission.