Newbie - Knitting a Wool Soaker and need help!

Hiya,
I'm a seasoned knitter, but a newbie to knitting soakers.
Turning to wool cause by LO has grown out of all his pockets and we need some large wraps to go over motherease and bedbugs.
Have found what looks a decent pattern.
http://christadovel.hubpages.com/hub/Hand-knit-Wool-Diaper-Cover-Pattern
Bought me some yarn - it's 100% wool, but says it's machine washable (Jarol ) - is this a problem? My friend advised only buy yarn that's handwash only.
ANy tips appreciated

Jx

Machine washable wool is often called superwash which means it has been treated so does not take lanolin as well as un-treated wool. I knitted my 1st soaker in superwash and just had to lanolise it much more!

The snapdragon pattern is free and easy too

WSS. You'd be much better to get some hand wash only 100% wool. That way they will rarely need any washing and just lanolizing every couple of months or so, providing you always use a wool wash to wash them. Ordinary detergents will remove the lanolin.