They should hire Mel Brooks.
An ad campaign! Eureka! Why didn’t anyone ever try that in Germany! “Juden weren nischt farflufen” would have worked miracles! During the bubonic plague, they could have signs saying “ Ye Jooos! didnae bring ye blacke death. ‘twere witches, aye trow.” Or “Nae blud gaeyeth intu the maeking of matza. His Maejesty quoth ‘out upon ye bubbe mayseh, me leal subjects. ‘tis nowt but flowr and water.’”.