How to eliminate odor from crawl space
A similar problem in my home was resolved by installing a small muffin fan to exhaust the air outside. A 50 cfm was more than adequate, so I added a series inductor (ballast) to reduce electrical usage and noise. A timer was also tried, but running full-time at low speed was more effective in reducing odors. If you live in an area where radon is an issue (e.g. over granite), this also reduces the amount getting into the house.

Wire through a GFIC, since this would be a wet location!

Disadvantages:


A hole is needed for mounting the fan.
The fan uses a small amount of electricity continuously.
The fan may make noise.
A small amount of air may be pulled into the house, raising HVAC costs.


So far, this has eliminated the smell in the house and has reduced humidity in the enclosed area (storage room rather than a crawl space), without noticeable impact on utility bills.