You may find some cheap Chinese "body massage" vibrating devices with adjustable speed settings, probably in pink. You may not want to trust them with any intim

You may find some cheap Chinese "body massage" vibrating devices with adjustable speed settings, probably in pink. You may not want to trust them with any intimate parts, but I've found that they're great at vibrating toner or flour down a paper funnel, so wouldn't be surprised if they also worked for this.