I know what you're trying to say Rob, and I'm doing a bit of "nit picking", but jute doesn't shrink, it swells

You can't add water to a fibre and make it smaller. The swelling fibres create tensions in the fabric whether it be a tufted carpet with a hessian backing or a mix of fibres as in a woven carpet ie jute and cotton or jute and polyprop.
In the end, the effect/consequences are the same, but the reason is different.
Safe and happy cleaning

Ken