I didn't succeed to make uwosh.snippets work.
I guess the add-on has been properly installed: TinyMCE has a new button, the icon of which being {{}} (BTW, no tooltip: too bad). When I click on it, a popup asks me to add a snippet with: "Select content Search :/.snippets" but I don't what to do.
I'm a bit lost.
Have you created any snippets in your new .snippets folder?
Can you give details of what you are trying to achieve?
It's likely that snippets is not the right answer to your problem?
For example themefragments, filteredcollections, eea.facetednavigation are all ways I've created custom search solutions in the past.