Try like this:

&lt;cms_index_index&gt;
    &lt;reference name="head"&gt;
       &lt;action method="removeItem"&gt;
           &lt;type&gt;js&lt;/type&gt;
           &lt;script&gt;prototype/validation.js&lt;/script&gt;
       &lt;/action&gt;
    &lt;/reference&gt;
&lt;/cms_index_index&gt;


The removeItem method receives 2 parameters. The type of the resource and the name of the resource. You were missing the type.

Removing a javscript from homepage
Suppose that I have made bread dough and it is supposed to be degassed around 90 min after kneading (t+90). Suppose that I have to leave home at t+30 and will be back sometime between t+120 and t+150. 

What is better for the dough, to degas it too early or to degas it too late? I know I can try to influence the duration of the first rising by changing the temperature (I could either put it in the fridge or in an oven preheated to 50°C, turned off and cracked open). But I doubt that the dough's internal temperature will change substantially during these short times. 

So, what is the better strategy? Warm it and degas early, or cool it and degas late? 

For the record, I am talking about a high-hydration bread (86%), with sugar, but no fat, 2.8% yeast. But if the hydration, leanness and yeast amount have an influence on the decision, I would like to hear about that too. (Assume that for any yeast amount, the time period before degassing has been calculated to be correct for it). 
