440 CFM Fan; Will This Inline Dimmer Work?

I read that a normal dimmer gimps the voltages to a fan, possibly killing it long term.

What about inline-plugs?

http://www.homedepot.ca/webapp/wcs/...ode+matchall&recN=112066&N=0&Ntk=P_PartNumber

http://cgi.ebay.ca/Ceiling-Fan-Box-...ultDomain_0&hash=item2c5cc0789c#ht_1141wt_648

Would this work as a fan control safely?

more exspensive but it's made for it
http://www.canfilters.com/accessories.html

Watch out for cheap controls.I stopped useing my speedmaster last year due to it would not kick my fan on sometimes when it was baffled down causeing my grow and lights to get extremly hot.Im getting ready to get one but Im buying a litlle better one this time.....