That's the most basic implementation of Wow / Flutter within scriptnode.
HiseSnippet 1838.3oc6Y0zTaaDFVxfLAHISRCcRN5C8.oSFFayGILclhwXLgowfGrCjazEo0XUKsqpzJ.mLcldr2541eD4T+Azq8Vmo+AZOz64eP66pUBoEK9PN.IsCjYx38c+548qmWs61zkpi87ntJpSztuCVQ81Zs5SXcWoKxjnrdME06p0.4wvtEDhp12A44gMTTUGYMt.0wGUI3u2sTUjEhniiEonrM0TG+BSaSVrzlU9JSKq5HCbaS6DidtJqqSIqPsn9.dFQqnhCRuGZe7FH9vxoo7bjWWE0OWa9xypOmwSMJWd9EWPGs.dwNnNcJMqwbysvyVrzrKhl6YKfKNuhZ9UMLYT2VLDC6AKZUpQ+VcoGRDav1ldl6Yg4MJozB1YgXkU5ZZYzLx33onnp0L1TMhvTMkVCSCyikGaxtWPGEhmQRilZtyBRkx.jTS.oQEP59ZszcMcXw8vwyjZqS.OXGD3aRBEwXUT+UsUnv.HrYrQ8v0cgFGOgoWnXwmT.9uG+Ec7I5LSJo.krAkg2jL8im3MSL9De2DENYWc5jZe7swkZYgcSsad3f6YMwoI916gceRgCPV93iGHn9x1z7WLaptPqSLPJYchIaSGbX65TKCtsh+6A8.JglM3Wub8ZHFh6TBkAiyA6xL4vQsF9.HMP3hFWqF1qGi5.IBC3+fHGpguEhIGNwSzB6.rGR9Ptih3Yx5mLQLCwXEOyXrKJDuuVSSld2zwXtTvHXotJvXXl4czVsSGrNKFfipU+UCaZXwLmFNQXZHrm7M+1gMKT+UkRMA7GzhC1cbwNHWbaZSKT+o8P1NV3s.L9jB6YQ060x703AyPbDPnJeDSq2EQHXKugIQJ+kD4jxVTelIY+FHlq4Q.84F91s.dcc7JgnCjolimCIZWj2lGWzBSLBZ7OvegcVh2VMryRQclH8aCL6Ppau.2Q3uUTukv16EXj2syQkTV1xhd3JTaGyvnTvGDHqI0puSWJwTmKRLhHjtrM0G1jP3FGhWMxcDgbn5TajoEOhukuGvgXrIoErNAkDUGYarqWvdNlVwYf+AY.aPMftFqNRGr48ahXc4oRbZIHtE6Ni9wwuRpQxPHQsQot4qZTUTAx.Exlan30P4dylHWXZ.COmbJm5HIHqDwy7VP1ZNwVut217d0QVJayiW3SJXWD16.kHu3aE5vW3x6FDppHoWOJgdIMpA0lSrLms979g9bIP+DZ1TCgIWB4Sk.4GOhAQchoeUh3QSf3aqQ8zgukhSFqLPTjKdlDcmVPShtyBj4cArRGEUxqlomCPVU0GHcEThRR35Ew.eTTd6p.0iATVMX5Q4xIBIAk63VPVbCSRnUHt3QCzQmP18pzhgcDoiwEBa0CenvtjTJ2zkmWFCqzFeDqMMXs.1jC.MjumSp8R.vc.Otgx.6cMbGjuEa.4JYGzeVJfFH4NUPOoVcW725CLJ8yBxq9Wudp2N1euTpH+66U4bP96VZPjWLil6aGf7BawYNytQ+coCcP9PXzAXlwHk0fhgeDB5yJRYLslcQdWYw2iedn9m+I9e+VFQc9fuzMKfNZeNMS8x9LpM39LNlCMj57NIH+JcC24MbmmBxm5sqArmOrxMbm2vcdMwc9lfXte4Jm6LZexL243Zdl6WF9ZWYdy6pAit6LQ8MHoY77NGFybRLlRzapWG9ewBbY5+SX8xq4fQm3vQSJJ4Dzwf1svYbNFsQkLZwmSsMxceLyK7toHXcwIeCN4y5Fb212XfgBN6p6uGb92isu79lTqFuqf6o8ptxkbCoSUJAPIC2Cf97blQZ.ocfRoAL7Qe4xbzWke7hUm5qePs+HL5Sbc4YN56KSuFE.fLw9DsXYs5ZbfxkXdiLEzoFsH6W33QSamM2Q4xmeX0if8ffrRbSmvA+g.ezdV.JkziAKpkLC7zSHk91RozwPNdkSpsiqU2xmwa+wkFKqhmtFK+w3opxUozd1nfq3689x1ennyI01Ac.N34tBtisOMncGpqcg0vDrq.Mm9Cd86WzG7x4B+fWapy.Hz1EQ7bnd3RRtGrsYaJA6II8DynbpynrbtFymHuzBQRihaJpClhDi6VUhDVNovlHhzhAskVoF76+Mp4etzpDdfSKLn4FaFGmmHhqoukGdGSCV2RImXr3xIE+bjqA3C0kh5FQ9ZrG8hcM1xOyRhwmxs9m+Cv6Ad47VMe.eNIo2JY7HL1xj+cEqBUJrfz3.L9IZg7JQRkyCaPIznqqO1quEl4Zt+9X4hSooPKyXH8dwRlpxVXKL+a9Sb7xW.kpPtAmzc3rEY+4aS0e8HMAbKvIOJ7e2mAbj+W+LfW7rOfO7iau3C0.d4xEBbkE9v3KuNd8vqi8vFo6R2UW7nq7j9aEHAzaR3IhavaWnjxAm7KmrgRF6pqKuTCLwxC6DmcXm3bC6DmeXm3BC6De5vNwmc9SjWQO7zI7bC3ybZtp3nsphuvIHMQ4eAPVAf2JYou can adjust the parameters of the oscillators and the delay range to fit your needs, but to get more than just a basic pitch modulation you'll need to think about ways of making the modulation less mathematical.