We are waldorfers, so I DO know your pain! We have just learned to let some things slide, and I think with as much "mommy competition" esp. in the dogmatic Waldorf world, you will find that all those families have a skeletons in their closets (skeletons in this case being a plastic/battery/character toy or two).
Take it with a grain of salt. Who cares about 1 Elmo toy if your child doesn't even know *who* elmo is? It's just a funny red monster! When the crap toys (yes, I teach my children to call them that!) start getting overwhelming, we take around the donation bag and start collecting in DS's room. Not a big deal, since it's been drilled into them since they were born that we don't like crappy toys. This means plastic/battery (which we actually never have b/c it drives me & DH nuts!)/ character/ or basically any toy that is ugly.
I don't tell inlaws that I don't want them to buy certain things, because that IS rude. They know what we buy, and we have gone shopping together MANY times, where MIL will say "Oh, this is so cute, you should buy it for DS", and I will say back "No thanks, I don't like plastic/etc. toys in our house". And i walk away. DS is 5 now, and she still buys the occasional crap toy (she buys him at least 2 dozen presents a year, so it's hard to avoid I suppose). The last one was a Buzz Lightyear that lit up and talked and everything. She tells me afterwards "I know you didn't want him to have it, but he wanted one so much, I just wanted to get him one!"
: Thankfully, the dang thing broke within minutes of DS opening it. I think only a wing broke, but it is a firm rule in our house we do not play with broken toys. DS was upset, not because I tossed it, but because his Gram would buy a cheap plastic toy!!
And the slightly embarrassing part was when DS told his Gram "thanks for the Buzz, but it broke right after I opened it, because it was a crappy plastic toy probably". And he wasn't saying it rudely, but innocently. I think that probably gets the point across the strongest.
Okay, this is becoming long-winded, but here's one more thing we do:
Have catalogs sent to in-laws (my mom only buys yardsale toys, so their's no point! and I don't feel bad about re-donating hers, b/c she only spent a dollar or two
). I have sent to them Magic Cabin/Hearthsong and Nova and Rosie Hippo. Then we get them, too. If a b-day/x-mas is coming up, I'll say, "Did you see that so-and-so in Nova catalog? DS would LOVE that! He would also love this widget... we were going to get him one, we were wondering if you wanted to get him one, and then we would get the other? Is there one you'd want to give him?" And they always are things the boys LOVE for a long time, and inlaws see that, so I think slowly they are getting the message!
Sorry so long-winded... I'm done now