It turned out that indeed, if you increase the amount each time by the amount of loss, after 5-10 spins you can return 100% of the bet with all expenses. You can find these codes on social networks, through newsletters, or on partner sites.
https://debate.socialism.nl/forum/showthread.php?tid=261598
http://forum.spolokmedikovke.sk/viewtopic.php?f=21&t=1101178
http://forum3.bandingklub.cz/viewtopic.php?f=49&t=1291053
https://www.ww2.site/forum/viewtopic.php?t=321578
https://forum.pcfoster.pl/topic/112723-casinos-en-linea-seguros-y-casinos-en-linea-de-peru/
http://www.lada-xray.net/showthread.php?p=135874#post135874
http://forum.bandingklub.cz/viewtopic.php?f=16&t=1658127
http://47.88.101.141/forum.php?mod=viewthread&tid=270775&extra=
http://forums.indexrise.com/thread-730083.html
http://www.lada-xray.net/showthread.php?p=181071#post181071