Aim: To compare oral hygiene (OH) differences during verbal or video OH instructions with or without images displaying poor oral health consequences. Materials and methods: Twenty-one healthy females (18–30 years) were randomly and equally divided into three intervention OH instruction groups: (1) verbal, (2) video-based, (3) video-based with image displaying the consequences of poor OH. Gingival bleeding on probing (BOP), gingival bleeding index (BI), and plaque score (PS) were assessed at baseline and after 4 weeks. Within- and between-group differences were assessed by non-parametric tests. Results: Plaque score only showed a statistical group difference after follow-up [H(2) = 9.214, p = 0.01]. The post hoc test revealed that group III showed a significantly lower PS than groups I and II (p = 0.04 and p = 0.017, respectively). No differences were observed in PS between groups I and II. Group I showed no follow-up reduction in PS, BI, and BOP, while group II showed a statistically significant reduction in BI only after follow-up (p = 0.028). However, group III showed a statistically significant reduction in BOP and PS (p = 0.023 and p = 0.045, respectively) but not BI. Conclusions: Verbal and video-alone OH instructions similarly affect gingival health, while participants who were exposed to images displaying the severe OH consequences had lower PS than verbal or video-alone groups. Clinical significance: The mode of OH instructions is not influential for optimum oral health. However, employing visuals highlighting the severe consequences of poor OH leads to short-term reduction of plaque accumulation.