Modulation comes in many forms and under many names: Chorus, Flanging, Phase Shifting and much more. There are subtleties between each effect, which is part of the joy of trying them out to see what works for you. The best thing here though is that there are affordable options, like the like beauty that is the AMS-3 Mod Station from Tom'sline
that give you a load of options to play with. If you then fancy upping your game then units from BOSS, Dreadbox, Fender, and MXR will be ready and waiting.